05000353/LER-2016-001, Regarding Manual Actuation of the Reactor Protection System When Critical Due to Wiring Design Error
| ML16209A265 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 07/27/2016 |
| From: | Libra R Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LG-16-083 LER 16-001-00 | |
| Download: ML16209A265 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3532016001R00 - NRC Website | |
text
Exelon Generation..
LG-16-083 July 27, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 2 Renewed Facility Operating License No. NPF-85 NRC Docket No. 50-353 10CFR50.73
Subject:
LEA 2016-001-00, Manual Actuation of the Reactor Protection System This Licensee Event Report (LEA) addresses a manual actuation of the reactor protection system (RPS) following a trip of both reactor recirculation pumps. The pump trips occurred during testing of a modification to the Plant Process Computer (PPC). The manual scram was directed by the unexpected/unexplained change in core flow procedure (OT-112) due to the tripping of the reactor recirculation pumps at power. An error in the modification wiring design caused an actuation of the reactor recirculation pump trip relays.
This LEA is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(iv)(A).
There are no commitments contained in this letter.
If you have any questions, please contact Robert 8. Dickinson at (610) 718-3400.
Respectfully, '"
~lvlfl-Richard W. Libra Site Vice President - Limerick Generating Station Exelon Generation Company, LLC cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, LGS
NRC FORM 366 (01-2014)
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LICENSEE EVENT REPORT (LER)
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- 1. FACILITY NAME Limerick Generating Station, Unit 2
- 2. DOCKET NUMBER 05000353
- 3. PAGE 1 OF 3
- 4. TITLE Manual Actuation of the Reactor Protection System When Critical Due to Wiring Design Error
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.
MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 06 01 2016 2016 -
001
- - 00 07 27 2016 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 100 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specify in Abstract below or in LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
Cause of the Event
The direct cause of the event was a circuit wiring design error that was implemented in the field and caused energization of the RRP ASD trip coils.
The root cause of the event was a failure of station personnel to appropriately apply THU error prevention techniques to identify the design error and prevent its installation and testing as part of the modification.
Corrective Actions Completed The isolation switch for the mis-wired circuit was opened to enable reset of the ASD trip coils.
The 2A and 2B ASDs were returned to service.
Corrective Actions Planned The wiring design error will be corrected and the Modification Acceptance Test will be revised to ensure the change is correctly tested per the requirements of the Acceptance Test Criteria.
The human performance aspects of the event will be addressed through several management actions that include reinforcement of proper standards and behaviors related to THU error techniques with station personnel.
Previous Similar Occurrences There was no previous RPS actuation in the past five years due to modification testing.
Component data System:
AD Reactor Recirculation System Component:
P Pump Component number: 2A-P201-DR Component name:
Reactor Recirculation Pump Manufacturer:
G080 General Electric Company Model number:
5K46385AA1